1. Field of the Invention
The present invention relates to an information processing apparatus, a mailbox management method, and a storage medium. More particularly, the present invention relates to an information processing apparatus in a mail service system for providing a mail service to businesses and institutions, a mailbox management method, and a storage medium.
2. Description of the Related Art
In recent years, with rapid spread of the Internet, in businesses and institutions that do not have resources enough to build their own infrastructures, demands for providing Internet-access service have been increasing.
If the businesses and institutions want to start an Internet service or a mail service, the businesses and institutions are required to build their own infrastructures or use service of Internet service providers (ISPs).
The ISPs provide not only the Internet-access service but also mail services such as e-mail management, transmission and reception of e-mails, the use of web-based e-mail, and virus-infected e-mail check.
The ISPs (hereinafter, referred to as mail service systems) providing such mail services register and manage e-mail addresses of users and store e-mails using mailboxes. In such mail service systems, contracts for the mail service with the ISPs are made by individuals, businesses, or institutions, and capacities of the mailboxes are determined for each subscriber.
For example, if the subscriber is an individual, the subscriber contracts with an ISP for the individual mailbox capacity of 500 MB. If the subscriber is a business or an institution, the subscriber contracts with an ISP for the mailbox capacity of 100 GB in a domain acquired by the contract.
As described above, while the capacity of the mailbox is set for each subscriber, if the user does not delete e-mails being stored in the mailbox, the used amount of the mailbox increases, and at last, when the used amount reaches the capacity limit of the contracted mailbox, the user is not able to receive a new e-mail anymore.
To solve the problem, for example, Japanese Patent Application Laid-Open No. 11-328059 provides a technique for warning a user about capacity excess when the used amount of an individual mailbox exceeds a predetermined value.
According to the system discussed in Japanese Patent Application Laid-Open No. 11-328059, a subscriber is warned in advance if the used amount of its own mailbox approaches the contracted set capacity. According to the technique, the problem that the subscriber is not able to receive a new e-mail can be avoided.
In other solutions for the problem, contracts of different mailbox capacities can be offered for each subscriber, or the contracts can be changed to increase the mailbox capacities in the middle of the contract.
However, in the currently available mail services, the mailboxes are managed on a subscriber-by-subscriber basis, and the service of changing the capacities of the mailboxes is provided only on a subscriber's basis.
Under the circumstance, if the subscriber is a business or an institution, the business or the institution acquires a domain, equally divides the capacity into the number of e-mail addresses in the domain, and manages capacities of individual mailboxes.
However, many of the businesses that subscribe to the mail services provided by the ISPs are small-to-medium-sized businesses. Depending on business contents, some employees rarely use e-mails, and some employees transmit and receive numerous e-mails. In other words, depending on the types of business of the employees, the frequency of using the mail services and the capacities of the e-mails are different, and consequently, the usage capacities of the mailboxes are different.